Vacuum casting device for gold-inlay work and the like.



B. DAVIS. VACUUM CASTING DEVICE FUR GOLD IVNLAY WORK AND THE LIKE. APPLICATION FILED IAN. 28. 1916. mm3-m.

III

WN NN INIIIZNTOFI Patented Mar. 2D

WITNESSES sanne: B. Davis, or JoHNs'roWn, PENNSYLVANIA.

VACUUM CASTING DEVXCE FOR GOLD-INLAY WORK AND THE LIKE.

Specification of Letters Patent.

lzntented Mar. 20, 1291"?.

Application filed January 2S, 1916. `Serial No. 74,770.

To all whom 'it may concern:

Be it known that I. FRANK B. Davis, a citizen ot the United States, residing at Johnstown, Cambria county, l.)ennsylvania, have invented a new and useful Vacuum Casting Devi'ce for (loldlnlay lVorl and the like, of which the following is a full, clear, and exact description, reference being` had to the accompanying drawings, forming part of this specification, in which:

Figure l is a view, partly in vertical section and partly in elevation, of a device embodying my invention.

Fig. 2 is a plan view of the same, part-ly broken away, and

Fig. 3 is a sectional'view, also partly broken away, and showing a modification.

My invention relates t0 vacuum casting devices for gold inlay work and the like, or any casting where sharp thin edges are required; and is designed to provide a cheap and simple device of this character especially adapted for use by dentists .or jewelers.

rlhe nature of my invention will be best understood by reference to the accompanying drawings, in which l have shown a preferred embodiment thereof and which will now be descrilied, it being premisedthat various changes can be made in the details ot' construction and arrangement of the parts without departing from the spirit and scope of my invention as defined in the claims.

Referring first to Figs. 1 and 2, the numeral 2 designates a hollow bowl of clay or other refractory material having the projecting stem 3, the whole being somewhat similar to an ordinary clay pipe.A The stern 3' has an interior passage Ll which communiu cates with the interior of the bottom portion of the bowl by one or more openings 5.

G designates a blower of any suitable or usual character having an outlet connection 7, to which is connected the usual flexible pipe 8 leading to the blow pipe 9. 10 designates the air inlet connection for the blower: and 11 is a piece of pipe which is adapted to be attached to the inlet 10, and to beconnected .to the stem S b v means of a detachable coupling 1'2, which is preferably flexible. The pipe l0 is provided with an opening 13 which may be controlled b v any sui-table valve, such' as the rotary sleeve valve indicated at 14.

The operation is as follows: Vhile melting the material for the casting in the bowl 2, the valve 14 is moved to open the air opening 13, so that there willl be no suction through the stem 3. use suction to draw the molten met-al down into the mold cavity and upon the investment, the valve 14 is moved to close the opening 3.

The dentist or other workman may be provided with a number of other different bowls 2 of different sizes adapted for diil'erent particular kinds of work, and any one "of these -anl be quickly and readily attached to the blower by means of the coupling 12. ln the modification shown in Fig. 3, the pipe 11.is omitted and the stem 3a of the bowl 2a is connected directly by the coupling 12a to the inlet pipe 15 of the blower i, This inlet pipe is provided with an escape opening similar to that shown in Fig. 1, and controlled lby the valve 16. ln

1When it is desired to this form l have also shown the bowl 2 as provided with the bottom proiections 17 which somewhat elevate the bowl from the support 18.

My invention provides an appliance of the character described which can be supplied at a very small cost, and which can be. conveniently used in connection with the 0rdinary blowers employed in blow-pipe work.

, By the use of clay or similar refractory material for the. bowl and its stem. l prevent'- any oxidizing action of the bowl. A bowl of this character has practically no expansion or contraction while heatingl and cooling. This is a serious objection to metal cups, since they expand and draw away from the investment, leaving a space between the investment. and the wall of the cup, causing a leak for the air.' Metal cups are also objec tionable in that the investment sometimes adheres to the wall of the cups and` `forms fissures. Clay boing a poor conductor of heat, the stem may be made sufliciently long, so that there will be no danger of burning the flexible connection with the suction-producing device.

l claim:

1. A device of the character described comprising a one-piece bowl of refractory material having an integral hollow stein communicating therewith. and means tor connecting said stem to the intake of a blower. substantially as described,

An appliance of the character described comprising an integral smaliportable bowl ot' refractory material and having a projecting hollow stem communicating with the interior of the bowl, a blower havvalve for controlling said opening, and a detachable coupling for coupling said stem to the blower intake, substantially as described, y

3. A device of the character described, comprising a bowl of refractory non-oxidizable material substantially free from ex- `pansion and contraction and having a rel'- atively long projecting hollow integral Stein communicating with its lowerV portion and adapted at its free end for connection to a Yeuction-producing device, substantially as described.

4. A device of the character (leecribed,

comprising a one-piece bowl of refractory Lemme material having an lyintegral hollow Stem communicating therewith,v the bowl vbeing arranged Yto receive the .investment material, while the stem is of sulicient length to prevent the end thereof lbecoming heated, a blower having anintake provided with an opening, a valve for controlling said open` ing, and a detachable flexible coupling for coupling said' stern to. the *blower* intake; substantially as described.

1n testimony whereof, I have hereunto Set my hand. f

' FRANK B. DAVIS. Y

i vvVitnessesi: i Y

M. B.' MCDONNELL, CHAS. H. REBER. 

